Fluid clutch with servo engagement



May 20, 1952 R. LAPSLEY 2,597,502

FLUID CLUTCH WITH SERV@ ENGAGEMENT IN V EN TOR.

R. LAPsLEY 2,597,502

FLUID CLUTCH WITH SERVO ENGAGEMENT May 20, 1952 Filed May :51, 1945 2 SHEETS- SHEET :a

Patented May 20, 1952 UNITED STES GFFIC FLUID CLUTCH WITH SERVO ENGAGEMENT Application May 31, 1945, Serial No. 596,835

4 Claims. l

This invention relates to transmissions, and more particularly is concerned with an improvement in the clutching mechanism by which the gear trains Within the transmission are clutched to the main shaft.

Primarily, the presentl invention is concerned with an improvement over the type of clutching mechanism shown in my copending application, Serial N o. 526,829, led March 15, 1944, and relates particularly to piston operated internal clutches carried within the gear members for clutching the gears to the associated shaft. It is understood, of course, that the clutch mechanism, per se, may be used in other devices than that herein shown and described.

One of the primary objects of the present invention is to provide a construction in which a relatively light piston load is required to set the clutch in operation so that the entire load for clutching the piston to effect movement of the vehicle is not produced by the hydraulic action. In this connection, it should be pointed out that with the present construction it will be necessary only in rare cases to provide any appreciable piston displacement for locking the gear to its associated shaft.

Another feature of the present invention is to provide a construction in which the shaft carries a hub member having circumferentially spaced oppositely acting pistons, these pistons acting on clutch discs engageable with side plates bolted to the annular gear member for clutching these plates into positive engagement with the hub member, whereby the gear is locked to the shaft. In a construction of this type, I have provided means for producing a servo action so that as the pistons are actuated, suitable roller members mounted on oppositely inclined cam surfaces act to produce increasing frictional pressure due to the relative displacement between the hub and the gear. This in turn provides a building up of the frictional engagement so that a small displacement of the pistons will operate to actuate the clutch. The angle of inclination of the raceways or ramps upon which the rollers operate is such as to insure return of the clutch plates to retracted position upon release of the hydraulic pressure.

With such a construction it is apparent that the load on the race or ramp upon which the rollers operate will never exceed that necessary to drive the vehicle, thereby never over stressing the parts, such as might occur if the piston pressure alone were relied upon to produce the clutching action.

Other objects and advantages of the present invention will appear more fully from the following detailed description, which, taken in conjunction with the accompanying drawings, will disclose to those skilled in the art the particular construction and operation of a preferred form of the present invention.

In the drawings:

Figure l is a sectional View through a transmission embodying the present invention;

Figure 2 is an enlarged detail view of a gear clutch showing the present construction;

Figure 3 is a diagrammatic plan View showing the relative arrangement of the pistons and roller members;

Figure 4 is an end View of one of the clutch plates looking at it from the outside;

Figure 5 is an elevational view of the hub member carried by the shaft; and

Figure 6 is an elevational view of surface of the clutch plate.

Referring now in detail to Figure 1, this figure illustrates one manner of operating a` transmission with the clutches of the type provided in the inside the present invention. There is disclosed in thisy figure a transmission housing 5 which is adapted to receive a shaft 6 mounted upon bearings 'I and 8, the shaft 6 having splined thereon a gear 9 adapted to'be driven from the gear I0 receiving driving torque through a fluid torque converter or the like. The gear 9 is in constant meshing engagement with a gear element I2 in the form of an annular ring gear, having bolted to the sides thereof side plate members I3, which in turn are mounted for rotation upon bearings I4 carried by the output shaft I5 whereby the gear and the side plate members I3 normally rotate relative to the kshaft I5.

Also splined on the shaft 6 is a sliding gear member I1 having a yoke hub I8 adapted to receive a shifter fork, whereby, when the gear I'I is slid axially into the position shown in Figure l, it has meshing engagement with the gear I9 rotatably mounted as by means of the bearings 20 upon the shaft 6, whereby the gear I9 is clutched tothe shaft 6 and in turn drives a second annular ring gear 22, having bolted to the sides thereof side plate members 23 mounted upon bearings 24 so that the gear element is rotatably journalled on the shaft I5. When the gear I 'I isy shifted axially to the right, it is adapted to move out of engagement with gear I9, thereby disconnecting drive from gear I9 to gear 22. Also, gear I'I can be shifted still further axially to the right to engage reverse gear member 25 rotatably journalled upon a lay shaft (not shown),` for providing a reverse drive through the transmission.

The shaft I5 is mounted at one end by means I of the roller bearing assembly 26 within the end wall of the transmission, and has the reduced portion 21 projecting outwardly through the opposite end Wall of the transmission and being journalled in the ball bearing assembly 28. The projecting end of the shaft portion 21 is provided with a speedometer gear 29 and with the hub portion 30 of a companion flange 32 of a universal joint. A suitable bearing cap 33 is provided for enclosing the speedometer gearing, and is provided with a suitable seal 34 fitting about the external surface of the hub 30 of the companion flange.

The opposite end of shaft l5, which is of reduced diameter as indicated at 35, is adapted to receive, as indicated at 36, an oil distributor member of the type also shown in my copending application, whereby oil from the automatic control system is introduced into suitable passage- Ways 31 and 38 leading into axial passageways 39 and 40 connecting through radial Ports with the respective hub portions 42 and 43 of the gear members 22 and I2, respectively, these hub portions being splined upon the surface of shaft l5. By means of a control valve such as described in my Hcopending application, oil under pressure is selectively transmitted through the distributor member 36 into either of the passageways 39 or 45, whereby each of the respective gear meinbes 22 or I2 may be selectively clutched to the Vshaft l for driving this shaft at a speed ratio determined by the relationship of the gears l2 and 9, or the gears 22 and I9. It is, of course, obvious that any number of gear trains may be so provided, each of thek gear trains containing one gear having the internal clutch arrangement as provided.

One of these clutches is shown more in detail in Figure 2; for example, the clutch mechanism for the gear 22. It will be seen from this drawing that the inner radial faces of the side plates 23v are provided with annular v-shaped grooves 50 which are concentrically arranged, and which are adapted to receivecorresponding annular ribs 'orproje'ctions 52 carried by the exteral'sifacesof clutch plate members 53. Each of the `clutch plate members 53 is provided on its inner annularY surface with axially extending concentric annular ribs 54, which in turn bear againstthe ends of pistons'55 carried within suitableeilcilniferentally spaced openings 56 in the hiib 'member 42. The pistons 55 are each provided with annular grooves 'intermediate their ends adapted to receive piston rings 51, and are held in endwise spaced relation by button portions 58, providing a slight clearance between the adjacent ends of the pistons through which the oil under pressure from the radial port connected with the passageway 39, as indicated at 58, flows in between the pistons to spread them apart.

Intermediate the openings 56 which receive thepistons 55, the hub member 42 is provided with 4elongated apertures 5i) through which are adapted to extend thespring members 60, these spring members beingsuitably connected at their endsrthrough pins 62 to the hub`v portions of the friction plates53, thesprings being locked in position by the pins entering through suitable slots inthe openings. provided in the hub portions of theplate members 53. These springs serve the function of retracting the plates 53 toward each other upon release of pressure between the pistons 55 to withdraw the platesfrom vclutching engagement within the clutches 50 of the side plates 23.

Intermediate each of the circumferentially spaced openings 56 in the hub member 42 there are provided smaller openings 65, which openings are adapted to receive a floating support member 66 carrying the piston rings 61, and also being provided with oppositely inclined ramp surfaces 53, as shown in detail in Figure 3. The insert 65 is provided with the same type of ramp surface at both ends thereof, the bottom of the depression being formed on a radial line of the axis of rotation. The two piston rings 61 are for the purpose of preventing axial movement of oil under pressure out through the openings 65.

Suitable circular inserts 10 are provided in recesses in the inner face of plate members 53 corresponding with the openings 65, the inserts 10 also having ramp surfaces 12. One of each opposed inserts 10 is held against rotation by means of dowel pins 13 while the other is free to rotate so that they will always be positively alined with the mating ramps 68 of the central member 65. Also, in machining such inserts, there is provided a tongue portion 13 at the top and bottom portions thereof, Which is for the purpose of pre- Venting radial displacement of the rollers 14 as by centrifugal action or the like. Thus, the rollers are held between the inner and outer tongues 13 against radial movement, and react against the opposite cam surfaces '68 and 12 to provide the servo action Whenever there is Aa tendency for relative rotation between the hub member 42 and the 'side plates 23 with the piston energized.

This camming action of the rollers on these oppositely inclined surfaces produces ka servo action caused by the drag of the friction plates53 engaging the side plates 23, causing the rollers to roll up the inclines and thereby exert an additional outward thrust upon the friction plates 53. This thrust is in direct proportion to the clamping action required to drive the vehicle, and the rollers `will climb up the ramps a sufficient distance to produce a pressure loading of the friction plates against the sideplates, which is never in excess of that necessary to producethe final clamping action, inasmuch as the relative movement ofthe hub member and side membersproduces the roller movement and when these members rotate vconjointly, no further movement of these rollersis necessary. The position of the rolls on the ramps automatically adjusts itself as the resistance to conjoint movement varies, but never exceeds that requiredto produce positive clutching action. Upon releaseof the pressure between' each pair of pistons 55, the springs 60 which have beenexpanded will contract to draw the frcioiiplates 53 together. collapsing thepistons 55, and, at the` same time, Acausing the rollers 14 to return to a bottoming position in the respective raceways 66 and 12. By dowelling one of the inserts 10 in fixed position, it will be apparent that through the rollers 14, the remainder of thelassembly, including the members 65 andthe opposite insert 10, will be held in alined position.

,In the operation of the device as thus described, oil under pressure is introduced between the pistons 55 through the passageway 39, port 58,V and the connecting drilled holes 80. This oil enters between the pistons'55, moving them axially apart. This in turn produces axial separation of the plates '53, tensioning the springs 60, and forcing the ribs 52 of these plates into the recesses 5U of the side plates 23. As the ribs 52 frictionallyengage in the grooves 5D, the relative rotation between the members 42 and I3 `produces an angular displacement of the plate members 53. This displacement causes the rollers 14 to ride up the opposite raceways 68 and l2, providing a camming action against the center member 65, producing an increased force axially outwardly on the plate members 53, forcing them firmly into the frictional engagement with the side plates 53, and thereby locking the gear member 22 securely to the hub member 42, and consequently to shaft I5.

It is therefore apparent that I have provided an improved type of clutching arrangement which eliminates the necessity of providing a large volume of fluid under high pressure to provide the clutching engagement, since all of the fluid that is required is that necessary to provide the initial contact between the side plates and the friction plates. From this point on, the rollers 14 function to provide the additional axial force necessary to produce positive clutching engagement.

I am aware that various changes may be made in certain details of the present construction, and I therefore do not intend to be limited except as dened by the scope and spirit of the appended claims.

I claim:

1. In combination a shaft, a hub splined thereon having a radial spider portion, a gear member encircling said spider portion and having radial side plates on opposite sides of said spider and iournaled on said shaft, clutch discs carried on opposite faces of said spider, circumferentially spaced piston means in said spider operable to spread said discs axially into contact with said side plates, servo cam means between said discs and spider responsive to relative rotation therebetween for forcing said discs into clutching engagement with said side plates, and said servo cam means being disposed alternately relative to said piston means.

2. In combination, a shaft, an annular gear member having radially inwardly extending axially spaced end plates rotatably journaled in said shaft, a hub splined on said shaft intermediate said end plates, said hub having a radial spider portion, clutch discs carried on opposite ends of said hub, a rst plurality of circumferentially spaced bores formed in said spider, a pair of oppositely facing pistons in each of said rst bores between said clutch discs, means for admitting fluid under pressure to the bores between said pistons for urging the latter into engagement with the adjacent clutch discs whereby the latter are urged into engagement with said end plates, a second plurality of circumferentially spaced bores alternately formed in said spider relative to said first bores, the axes of said second bores lying radially outwardly of the axes of said first bores, servo cam means in each of said second bores between said clutch discs responsive to relative rotation between the latter and said spider for forcing said clutch discs into clutching engagement with said end plates.

3. In combination, a shaft, an annular gear member having radially inwardly extending axially spaced end plates rotatably journaled on said shaft, a hub splined on said shaft intermediate said end plates, said hub having a radial spider portion, clutch discs carried on opposite ends of said hub, a first plurality of circumferentially spaced bores formed in said spider, a pair of oppositely facing pistons in each of said first bores between said clutch discs, means for admitting fluid under pressure to the bores between said pistons for urging the latter into engagement with the adjacent clutch discs whereby the latter are urged into engagement with said end plates, a second plurality of circumferentially spaced bores alternately formed in said spider relative to said rst bores, the axes of said second bores lying radially outwardly of the axes of said first bores, servo cam means in each of said second bores between said clutch discs responsive to relative rotation between the latter and said spider for forcing said clutch discs into clutching engagement with said end plates, a plurality of circumferentially spaced apertures alternately formed in said spider relative to said first bores, the axes of said apertures lying radially inwardly of the axes of said first bores, and spring means disposed in said apertures having connection at the ends thereof to each of said clutch discs for normally biasing the latter out of clutching engagement with the adjacent end plates.

4. In combination, a shaft, an annular gear member having radially inwardly extending axially spaced end plates rotatably journaled on said shaft, a hub splined on said shaft intermediate said end plates, said hub having a radial spider portion, clutch discs carried on opposite ends of said hub, a first plurality of circumferentially spaced bores formed in said spider, a pair of oppositely facing pistons in each of said rst bores between said clutch discs, means for admitting fluid under pressure to the bores between said pistons for urging the latter into engagement with the adjacent clutch discs whereby the latter are urged into engagement with said end plates, a second plurality of circumferentially spaced bores alternately formed in said spider relative to said first bores, the axes of said second bores lying radially outwardly of the axes of said first bores, servo cam means in each of said second bores between said clutch discs comprising an insert having tapered cam surfaces at the opposite ends thereof, inserts in the faces of each of said clutch discs, said last named inserts having tapered cam` surfaces, radially disposed antifriction members normally disposed between the pairs of adjacent cam surfaces at the base thereof and operable to ride up the oppositely disposed cam surfaces upon relative rotation between said clutch discs and said spider for forcing said clutch discs into clutching engagement with said end plates.

ROBERT LAPSLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 506,517 Leibert Oct. 10, 1893 1,748,827 Boltshauser Feb. 25, 1930 1,783,513 Maurer Dec. 2, 1930 1,789,271 Cappa Jan. 13, 1931 1,914,688 Furnas June 20, 1933 1,953,568 Rose Apr. 3, 1934 2,063,444 Lambert Dec. 8, 1936 2,081,824 Lambert May 25, 1937 2,220,542 Peterson NOV. 5, 1940 2,221,399 Geyer Nov. 12, 1940 2,245,988 Lambert June 17, 1941 2,333,682 Schneider NOV. 9, 1943 2,372,123 Sadler Mar. 20, 1945 2,375,854 Lambert May 15, 1945 2,398,806 Schneider Apr. 23, 1946 

